1. Field of the Invention
The invention relates to the display of electronically detected signals, and more particularly to interface devices permitting communication between an optical character reading wand and an electronic cash register having a display and a keyboard.
2. Brief Description of the Prior Art
Point of sale devices having keyboards, displays, and processing capability are known. For example, electronic cash registers are available from Sweda International, Inc., 34 Maple Ave., Pine Brook, N.J. 07058. The available models include model 35 as well as Models 600 and 800. The Model 800 is intended to be used with various peripheral devices, including, for example, an optical character recognition wand for reading labels on merchandise items. Other manufacturers include NCR, Dayton, Ohio, Models 280, 255, 2140, 2151; Data Terminal Systems, Maynard, Mass., Model 500 Series; MKD, Cherry Hill, N.J., Comtar 9, and TRW Systems.
Optical character recognition (OCR) wands are available from Recognition Products, Inc., P.O. Box 5569, Dallas, Tex. 75222. One such wand provides an ASCII output representative of a symbol detected by the wand on the label. Prior to transmission of a new character from the wand to the point of sale terminal, a signal is required from the terminal indicating readiness for acceptance of a signal. Other than in asychronously operating wands, such signals must be generated within the point of sale terminal and a "handshaking" sequence is required for transmission of information. Another OCR manufacturer is Caere Corporation, Mt. View, Calif. 94043.
Point of sale terminals and wand readers of the type currently available do not generate the interactive control signals for interfacing one with the other, thus hampering the availability of such wands for the contemplated terminals. Moreover, many electronic cash registers are on the market which were not designed with the contemplation of possible use of a wand, and do not have the facility for generation of any such "user ready" signal for interfacing therewith.
It is accordingly a primary object of the present invention to provide an interfacing means between a data reading wand and a point of sale terminal for enabling the combined use of such devices without requiring the terminal to generate any control signals for the wand.
Accordingly, with the present invention, terminals both with the intended capability of interacting with a wand as well as simpler electronic cash registers without such a capability would be operated in conjunction with a data reading wand, whether the data is read optically, magnetically, electrostatically, or with the aid of any other technology.
Lincoln-Hall Research Compnay of Lima, Ohio, manufactures typically available liquor dispensing equipment utilizing cash registers having encoded keyboards with preset outputs. Actuation of a single key, labelled "Vodka," for example, causes display and registration of a transaction price. The equipment includes a dispenser, providing a single datum of information to the equipment, indicating the conclusion of a transaction wherein a particular liquor was dispensed. The datum of information is similar to that produced by depression of a key on the keyboard and similarly causes display and registration of a full transaction price. Such equipment suffers from the limitation of the number of keys on the keyboard (and hence of possible transactions) and the requirement of special storage and decoding equipment. The present invention provides a full flexibility of data format, and thus for reading of any amount of data by means separate from the keyborad. Such operations save many manual key depressions in entry of data concerning a single transaction into a terminal, whether for computation, storage, or display. Display as used in the present disclosure refers both to transient displays, including visually perceived electronically generated alphanumeric LED or LCD displays and the like, and permanent hardcopy displays, including printed journals, receipts, and the like.
Gott U.S. Pat. No. 4,088,981 discloses the concept of a wand having its own keyboard in communication with a plurality of displays and keyboards. The wand generates a plurality of signals, encoded similarly to the coding of signals generated by one of the plurality of keyboards associated therewith. No indication is given, however, of the interaction between the display unit and the wand other than the disclosure that "enable" and "transmit" keyboard buttons are available on the wand.
The instant invention simplifies the data signals which are communicated to the terminal by decoding the same and effecting instead a set of signals directly duplicative of signals generated by switch closures on the display keyboard. Moreover, a control signal is generated on the interface to eliminate the necessity of communication between the terminal and the wand, otherwise known as "hand-shaking."
Cunningham U.S. Pat. No. 3,812,347 teaches an interface 800 which includes thereon a timing module 818 triggered by a sync detector. The interface is used in conjunction with an optical reader, but merely provides for an indication to the operator of readiness to read or necessity for rereading a label, responsive to the detected or undetected synchronization. The present invention generates a timing signal to satisfy a requirement of the wand, specifically to provide an indication of readiness on the part of the terminal to accept further data, irrespective of whether the terminal is or is not so ready. Since many point of sale terminals include therein audible "beeper" sounds to indicate an inaccurate or erroneous data reading situation, the present interface accordingly relies upon the operator to detect whether the terminal was in fact ready to receive the data. By thus removing the feedback nature of the signals required to be interchanged between the terminal and the wand, a great simplicity in circuitry results and a saving in manufacturing cost ensues.
Mak et al. U.S. Pat. No. 3,238,501 utilizes a self-clocking feature in a wand. Such a synchronous operation, however, requires additional circuitry on any receiving terminals. The present invention, by utilizing arbitrary timing generators on an interface, synchronizes the wand output data with the decoding capability provided on the interface in a simple and inexpensive manner.
Other references of lesser interest include Ferry U.S. Pat. No. 920,940, where the keyboard of a typewriter and an adding machine are paralleled, and Chadima et al. U.S. Pat. No. 3,991,299 wherein a bar code reader bypasses a keyboard and generates signals equivalent to those converted from the keyboard for direct insertion into memory. An audio alarm is provided for the operator to retry transmission if the data is bad.
Additional references include Neff U.S. Pat. No. 4,048,617, illustrating a feature of a wand available from Recognition Products, Inc. Additionally, LeMers U.S. Pat. No. 3,413,447 connects a wand to a cash register and provides for actual operation of the cash register keyboard keys by the wand output. Dobras et al. U.S. Pat. No. 3,792,236 includes handshaking signals circuitry associated with a bar code reader, and Humbarger U.S. Pat. No. 3,585,367 includes a clock generator in a wand, along with a sample signal generator responsive to the clock.